Sewing machine



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SEWING MACHINE Filed May 29, 1925 '7 Sheets-Sheet 3 'C0 Cf) lnVemToT. Axel FCorlson e bym MMIWJ? ATyS.

Dec. 10, 1929. A. F. cARl soN 1,738,868

SEWING MACHINE Filed May` 29. 1926 '7 SheetS--Shee 4 F14. if g 35 3A y Dec. 1Q, 1929. A. F. CARLSON 1,738,368

SEWING MACHIE Filed May 29, 192e 7 snets-sneet 5 lrwenor.

Axel F. Carlson ATyS.

Dec.. 10, 1929. A. Ff, CARLSQN I 1,738,868

SEWING MACHINE Filed May 29, 1926 'T Sheets-Sheet 6 Fig..

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8 Dec. 10, 1929. A. FL c'ARLsoN 1,788,868

SEWING MACHINE Filed May 29, 192e "7 sheets-sheet 'r Fi g. 10.

lnvenToT. Axel F. Carlson Patented Dec. 10, 1929 AXEL F. CARLSON, OF CAMBRIDGE, MASSACHUSETTS, ASSIGNOR T0 THE REEUE BU'ITN HOLE MACHIKNE CFEPAEETY, 0F BOSTN, MASSACHUSETTS,

MAINE A CURIPORATN 0F SEWING MACHINE Application filed May 29,

This invention relates to buttonhole sewing machines and particularly to the worli clamp and novel means for closing the clamp onto the work and then spreading the clamp to place the cloth under slight tene sion while the buttonhole stitches are being formed, said means operating to contract the clamp and then to' raise it at the end of the sewing operation.

ln order to give an understanding of the invention l have illustrated in the drawings a selected embodiment thereof which will now be described after which the novel features will be pointed out in the appended claims.

ln the drawings, Fig. 1 is a side view of a sewing machine embodying my invention;

Fig. 2 is a plan view of the work-supporting arm and work clamps thereon;

Fig. 3 is a side view of Fig. 2;

l is an enlarged section on the line $41, Fig. 1; l

Fig. 5 is an enlarged section on the line 5.-5, rig. e;

Fig. 6 is a fragmentary detail view showing the operation of the latch for holding` the clamps open;

Fig. 7 is a section on the line 7 7, Fig. 5;

Fig. 8 is an enlarged section on the line 8--8, Fig. l;

9 is a section on substantially the line 9 9, Fig. 8;

Fig. 10 is an enlarged section on the line 10-10, Fig. 1.

'llie present invention is shown as em bodied in a sewing machine similar to that illustrated in my co-pending application Serial No. 79,523, filed January 6th, 1926, said `machine being a two-thread button-- hole sewing machine. This sewing machine has the frame 1 from which extends the usual overhanging arm 2 carrying the upper thread-manipulating mechanism comprising the usual needle 3 which is mounted in a vertically-reciproeating needle bar 4. The frame also has extending therefrom a lower work-supporting arm 5 on which the work w is supported, this work-supporting arm 5 carrying the under thread-manipulatmg mechanlsm which may be of any ap- 1926. Serial No. 112,507.

proved type but which is not herein shown.

The operating mechanism is driven from a driving shaft 6 which in turn is actuated from a constantlyerotating driving pulley 7, the latter being1 driven by the driving belt 8. This driving pulley 7 is connected to and disconnected from the driving shaft 6 through the medium of a suitable clutch, (not shown) situated in a recess in the pul ley 7, said clutch being controlled by a cone-shaped clutch actuator 9 which is slidably mounted on the shaft 6. Movement of the clutch actuator toward the left Fig. 8 throws the clntch into engagement and movement to the right into the position shown in Figs. 8 and 10 releases the clutch.

This clutch actuator 9 is cont-rolled by a clntch-'controlling rod 10 which slidably mounted in the frame and which `has fast thereon a forked arm 11, the forlr of which engages in a groove 12 in the clutclr controlling member 9 so that movement of the rod 10 in the direction of its length will throw the clutch into engagement or release the clutch. The clutch-actuating rod 10 is given its clutch-engaging movement by means of an elbow lever 13 pivoted to `the frame at 111, the vertical arm 15 of said elbow lever engaging the end of the rod l0. When the horizontal arm of the lever 18 is pulled downwardly the elbow lever will be turned thereby shifting the rod 10 to the left Figs. 1() and 8 and throwing the clutch into engagement. When the clutch is thus engaged the rod 10 is latched in its operative position by means of a latch 16 adapted to engage a notch 17' in the rod and when the latch is released the rod will be automatically shifted into a position t0 disengage the clutch by means of a spring 18, all as shown in my above-mentioned application. lt might be added here that suitable means, not shown, is provided for automatically releasing the latch 16 when the stitching on the buttonhole has been com pleted, all as shownin said co-pending application Serial No. 79,523.

rlhe elbow lever 13 may be operated in any suitable way. It is herein shown as having a link 19 pivotally connected to the 1 mechanism for bringing the machine to rest.

This stopping mechanism comprises a stop motion block 24 which is fast on the rod 10 Y and which carries a stop dog 25 that is adapted to co-operate with a stop cam 26 to stop the` machine. This stop cam is fast on the 'shaft 6.A When the rod 10 has been shifted tothe left Figs. 10 and 8 to throw the clutch 'into ye'ngagement the stop dog 25 is in a positionat one side ofthe path of travel of the Vstop cam.l When, however, the latch 16 has been released at theend of the sewing operation the rod 10 will be shifted to the right by its spring 18 and this will bring the stop dog 25 into the path of movement ofthe stop i cam and when'dur'ing the rotation of the shaft the stop vcam engages the stop dog the maychine ywill'be brought to rest, all as described inthe'abv'e-mentioned application.

j themachine is at rest through the mediumv The work w ris held by a suitable work holder comprising under clamps 27 and upper clamps' 28. Both, clampsA are mounted on a Work-'supporting plate 29 which in turn is supported onthe work-supporting arm 5, so

that it can move longitudinally of the arm and also transversely thereof. The movement longitudinally of the arm is that which gives the work its feeding movement during the stitching along the side ofthe buttonhole and the movement transversely of the arm is that which gives the work a jogging moveil `*ment 'for forming the barring stitches at the endr ofthe buttonhole, all as usual in butl't'onl'iole sewing machines of this type.

The upper work clamps 28 are carried by arms 30 which extend from the upper end of a'rckin'g member 31 that is pivoted on a shaft v 32 carried by the clamp plate 29. These uplpercl'ainps are yieldingly held against the 4,work by means of springs 33 which encircle Aof a'flateh v37 and the following mechanism. `'lirlounteilin bearings inthe clamp plate 29 is a rock shaft 38 having rigid therewith an offset crank 39 (see Figs. 2, 3 and 5,) the end of which crank engages the under side of an arm 40 fast on a rock shaft 41 that is journalled in a bearing on the under side of the rocking member 31 (see Fig. 5).

The arms 39 and 40 are tied together through the medium of a band 42 and the arm 40 is provided with laterally-extending pins 43 situated underneath the upper clamp arms 30. When, therefore, either of the shafts 38 or 41 are rocked the pins 43 will engage the under side of the clamp arms 30 and raise the clamps.

The shaft 38 has at its end an arm 44, said arm carrying a projection 45 adapted to be engaged by the latch 37. This latch not only holds the clamps open by its engagement with the projection 45 but also operates to lift the clamps at the end of the buttonhole by mechanism which will be presently described.

When the machine lis Iirst started the latch 37 is automatically released from the projection 45 as shown by dotted lines Fig. 1 thereby to allow the work clamps to close by the action of the springs 33. This release of the latch is accomplished by the following mechanism.

Pivoted to the bed frame is a swinging arm 46 carrying a pin 47 adapted to engage a. cam surface 48 on the under side of the latch 37. This swinging arm or lever 4G is connected by a link 49 to an elbow lever 50, the latter having a depending rod 51 pivotally connected thereto which extends through the head 20. This rod 51 has a collar 52 thereon with which the head 2O engages so that downward movement of the starting treadle will operate through the connections above described to swing the lever 46 from the full to the dotted line position Fig. 1 during which movement the pin 47 will engage the cam surface 48 and thus raise the latch 37 and release it from the projection 45. As soon as the latch is released the springs 33 operate to close the clamps as will be readily understood. The collarV 52 is adjusted so that on the initial downward movement of the head 20 the latch will be released while the collar 22 is so adjusted that the clutch will not be thrown until after the head has made its initial downward movement and the clamps are released.

The work clamps are so constructed that when they are closed onto the work they will be separated or spread thereby to put the cloth under slight tension while the buttonhole is being sewed. The construction is also such that when the clamps are raised they are automatically closed together or contracted again.

The rock shaft 41 carrying the lifting arm. 40 has rigid therewith two heads 53 (see Fig. 4) each of which is formed with a cam groove `5,4 (see Fig. 2), and eachclamp armI 30 is prolili] lll vided with a projection 55 which entersone ot the cam grooves 54.

Means are provided whereby alter the latch 37 has been releasedtrom the projection l5 and the clamps are closed onto the work the shalt el will he turned into the dotted line position llig. 5 and during this turning movement the action ont the cam grooves 54: will opcrate to spread the clamp arms 30, it being understood that said arms are pivoted at their rear ends as shown at 56. This turning movement otI the shaft ll to spread the clamps is derived positively from the swinging movement el the lever lo by which the latch is released. For this purpose said lever has rigid therewith an arm 57 which during the swinging movement of the lever 4:6 will engage a roll 58 on the end of the projection 45. The end ol this lever 57 is cam shaped so that the swinging movement oi' the lever into the dotted line position lig. 1 will give a positive turning movement to the shalt 38 thus s vine;- ing the arm 3Q downwardly and since saidv arm is tied to the arm l() by the connection l2 this turning movement .elI the sha'i't 38 and arm 239 will be communicated to the arm l0 and the shaft ell.

rlhe arm 57 is so positioned that it will not engage the roll 58 until alter the latch 3l' has been released by the action oic the pin l? engaging the cam 48. Consequently the turning or the shatt ll to spread the clamps does not occur until ritter the clamps are closed onto the worlr. The extent oit' this spreading movement is determined by a stop screw 76 which is carried by the part 3l and with which the tail lo oli the lever 4 0 is brought into engagement wl e the shatt lll is given its turning movement. lll/'hen the work clamps have been closed and spread the arms 39 and l0 are in the dotted line position Fig. 5 with the lifting pins l-3 separated 'from the underside ol the armsj in which position they remain until thn lamps are opened again.

lilith this constructionv thereforea when the head 2O is depressed the initial depressing movem :it will raise the latch 37 and release the worl: clamps allowing them to close and then further movement oit the head will bring the arm 5'? into engagement with the projection 5S and thus spread the clamps and still 'lurther downward movement ot the head will threw the clutch to set the sewing mechanism into operation. The spreading oli the clamps, theretfore, does not occur until after they have been brought into contact with the work.

At the end ot the sewing operation the clamps are automatically opened by means controlled by the stop mechanism.

rThe latch 37 is pivotally connected to a lever 59 which is mounted on a roch shaft 60 journalled in the frame, said rock shaft having another arm 6l connected thereto which is adapted to he actuated by a cam 62 journalled on a stud or shaft G3. This cam is normally at rest while the stitch-forming mechanism is in operation but is adapted to be clutched to a constantly-driven member 611- when the stop motion acts to bring the stitchlorming mechanism to rest. The constantlydriven member G-l is in the lorm of a gear loosely mounted. on the stud 63 and meshing` with a gear 65 which is connected to and actuated 'trom the driving pulley 7. The cam 62 is automatically clutched to the `constantlydriven member Gl through the medium ot a clutch pin (36 in a manner similar to that shown in my co-pending application Serial No. @35h23, and also in a manner similar to that shown in thc co-pending application ot John lhiewicZ. Serial No. 75,518, tiled December 15th, 1925. i

lfilhile the sewing operation is in progress the clutching pin G6 is withdrawn and is held withd awn by the clutch dog GY. When the stop motion foperates to bring the stitchforming mechanism to rest the clutch dog 67 is released from the clutch pin 6h and the latter is thrown into clutching engagement with the constantly-rotating member 6l by means of a sprii f @il thereby clutching the cam to the constantly-rotating member. To aeomplish this the clutch dog is mounted on a rock shalt 69 which has an arm 70 rigid therewith, said arm carrying a projection 7l which is acted on by an arm 72 'tast on the stop motion block 2241.-.` When the stop motion acts to bring the machine to rest the engagement ott the stop camQG with the stop dog 25 will give the stop motion bloclr a slight turning movement about the rod l() so that the arm "l2 will be moved momentarily into the dotted line position llig. 9 thus engaging the projection il and turning the arm TO and shalt rllhis slight turning movement of the shalttltl is suliicient to raise the clutch dogl 6l" and release it 'from the clutch pin G6 thus allowing the clutch to become operative.

lllhe clutch device by which the cam is clutched to the constantly-rotating member is a one-revolution clutch and after one complete .revolution oli the cam the clutch pin will be withdrawn trom its operative position. hy the clutch dog il?.

llifhen the cam G2 is at rest during the sewing operation the high part thereof engages the lever "el thus holding the latch in its retracted position. fis the cam starts rotation the high part passes out from under the arm 6l and the roch shalt GO is turned through the medium ot a spring lil@ thereby moving the arm 59 toward the lett Fig. l and projecting the latch 3l" Jforwardly. ln said Fig. il the arm lle-l and projection l5 are in the position they assume when the clamps are closed, and the 'liorward movement ot the latch is sutlicient that it will drop over the projection d5, as shown by dotted lines ltig. (l. frs the cam completes its rotation the high part thereof will engage the lever 61 thereby swinging the arm 159 to the right Fig. 1 and retractingjthe latch, said latch during Vits reti-actin Ymovement swinging the arm 44 rearwar ly-and `thus 4raising the clamps.

The cam 62 comes to rest in the position shown in Fig. l and the work clamps'are thus helduraised by the latch, said latch holding the clamps vraised until the machine is started for the next stitching operation.

When the latch 37 lis actuated to open Athe clampsas above described the initial retracting movement of the'latch will swing the arms 39 rand 40 upwardly from the dotted line'post-ion to the full line position Fig. 5 thereby to 4'bring the pins 43 in engagement with 'the under side of the clamp arms. During this movement the shaft el and the heads 'thereon are turned and operate to contract the. clamps. Further retracting movement of the latch willV give the arm liet, shaft 38, arms '39 and 40 a further swinging movement whichwill operate to raise the clamps as will ybe readily understood.

yIclaim:

l. In a `sewing machine, the combination with stitch-forming mechanism, of two work clamps for holding the work, a spring device for holding the clamps yieldingly against the work, a latch to hold the clamps raised when the machine is at rest, a swinging member operative during its initial movement to release the latch to allow the clamps to close clamps, a spring for holding said clamps yieldingly against the work, alatch to hold the clamps raised, a cam device for spread- .ing the clamps, and a movable actuating member operative duringits initial movement to release the latch and during further movement' to actuate the cam device to spread the clamps.

4. In a sewing machine, the combination with stitch-forming mechanism, of a clutch for driving said mechanism, workclamps, a spring to hold the work clamps yieldingly against the work, alatch by which said work clamps are raised, an actuating device and connections whereby d-uringthe initial move- .ment of the actuating device vthe. latch will be released to allow the clamps to `close and during further movement the clamps will bespread and during still further movement the clutch will be engaged to start the stitchforming mechanism in operation.

5. In a sewing machine, the combination with stitch-forming mechanism, of a clutch for driving said mechanism, work clamps, a spring to hold the work clamps yieldingly against .the work, a latch by which said work clamps are raised, an actuating device and connections whereby during the initial movement of the actuating device the latch will be released to allow the clamps to close and during further movement the clamps will be spread and during still further movement the clutch will be engaged to start the stitchforming mechanism in operation, stopping mechanism to bring the machine to rest and means actuated by the stopping mechanism to raise the clamps when the stitch-forming mechanism has been brought to rest.

6. In a sewing machine, the combination with stitch-forming mechanism, of driving and stopping mechanism therefor, of two Work clamps for holding the work, a spring to .hold the clamps yieldingly against the work, a latch to hold the clamps raised when the machine is at rest, an actuating device operative during its initial movement to rclease the latch and during a further movement to spread the clamps, and means operated by the stopping mechanism to raise the clamps when the stitch-forming mechanism is brought to rest.

7. In a. sewing machine, the combination with stitch-forming mechanism, of driving and stopping mechanism therefor, workclamping means for holding the work, a spring to hold the clamping means yieldingly against the work, a rocking member for raising the clamps, a latch engaging said member for holding the clamping means raised, said latch being separate from the driving and stopping mechanism, a movable member which upon its initial movement releases the latch to allow the clamping means to close and upon further movement starts the driving mechanism in operation, and means actuated by the stopping mechanism when the stitch-forming mechanism is broughtto rest to cause the latch to engage the rocking member and open the clamping means.

8. In a sewing machine, the combination with two work clamps each carried by an arm having a follower stud, a rocking member having two cam grooves, one for each follower stud, means to turn the rocking member just after the clamps are closed to spread the clamps, and a latch to turn the rocking member when the clamps are opened to contract the clamps.

9. .In a sewing maehii e, the combination with two work clamps, an arm by which each clamp is supported, each arm having a follower stud, a shaft having two cam grooves, one for each follower stud, a spring device llO for holding the Work clamps yieldingly against the Work, a latch for holdingl said clamps raised, a movable member operative during, its initial movement to release the latch thereby allowing the clamps to close and during` its further movement to turn the shaft thercoy to spread the clamps.

l0. ln a serving,` machine, the combination with stitcli-formingmechanism, et driving and stopping mechanism therefor, vvorltclamping means, a spring device tor holding` the clamping means yicldingly against the Work, a clamp-lifting member, a latch cooperating,T therewith to litt the clamping; means and hold it raised, means to release the latch to alloiv the clamping means to close onto the vvorl, a cam device which is no1'- mally stationary during the sewing operation, means actuated by the stopping mechanism in bringing the stitch-forming mechanism to rest to render said cam operative, and means actuated by the cam to manipulate the latch thereby to operate the clamp-lifting member and lii't the clamping means.

ll. In a sewing machine, the combination with stitch-forming mechanism, of driving and stopping` mechanism therefor, Work clamps, a spring for holding said Work clamps yieldingly against the Work, a rotary cam device, a constantly-rotating member, means actuated by the driving1 and stopping mechanism in brin,gingthe machine to rest to couple said cam device to the constantlyrotating member and then to release said cam device when it has made a complete rotation continuously, and means actuated by said cam device to raise the clamps.

l2. In a sewing` machine, the combination with stitch-forming mechanism, olf driving and stopping,` mechanism therefor, a starting` device by Which the driving` mechanism isset in operation, Work clamps, a spring 'for holdime` said Work clamps yieldingly against the Work, a rotary cam device, a constantlyrotating,` member, means actuated by the driving and stopping mechanism in bringing the stitch-forming mechanism to rest to couple said cam device to the constantly-rotating member and then to release said cam device when it has reached a predetermined position, means actuated by said cam to raise the clamps, and means actuated by said starting; device to release the clamps vvhile the cam remains in such predetermined position.

i3. lin a serving; machine, the combination with stitch-torminp,1 mechanism, or driving and stopping; mechanism therefor, Worlt clamps, a spi-ine,` :torholding1 said Work clamps yieldine'ly a 'nst the vvorli, a cam device,

constantly-rotating; member, means actuated by the drivin@ and stopping mechanism in bringing the stitch-:termina mechanism to to'couple said cam device to the constantly-rotating member, a clamp-raising latch, and means actuated by the cam device rest to couple said cam device to the coni ntly-r tating; member and then to release said cam device when it has reached a predet -n iiiincd position, a clamp-raising latch, and means actuated. by the cam device to operate the latch and thereby raise the clamps.

lf, ln sewing machine, the combination with stitch-termingl mechanism, ot driving and stopping mechanism therefor, Work clamps, a spring ttor holding said clamps yield' ,gly against the ivorl, a cam device, a constantly-rotating member, means actuated by the driving` and stopping mechanism bi" the stitch-formine` mechanism to rest to couple said cam device to the constantly-rotating member and then to release said cam' device when it has reached a predetermined position, a clamp-raising latch, means actuated by the cam device to operate the latch and thereby raise the clamps, and means to release the latch While the cam remi. in such predetermined position.

1G. ln a sewing,` machine, the combination with stitch-tormingg1 mechanism, of driving and stopping mechanism therefor, tvvo Work clamps tor holding the work, a spring device tor holding; the clamps yieldingly against the Work, a rotary cam device, a constantly-rotating` member, means actuated by the driving` and stopping` mechanism in bringing the stitch-forming; mechanism to rest to couple said cam device to the constantly-rotating; member, a clamp-raising latch, means actuated by said cam device to operate the latch and thereby raise the clamps, said latch leiding the clamps raised While the machine with stitch-termine; mechanism, oi driving,r

and stopping` mechanism therefor, tivo Work clamps 'tor holding; the Work, a spring1 device 'lor holding' the clamps yieldingly against the Work, a rotary cam device, a constantlyrctatiim,v member, means actuated by the driv-` ing); and stampingl mechanism in bringing the tch-termin,a` mechanism to rest to couple said cam device to the constainclyrotatingmember, a clamp-raising` latch, means actnated by said cam device to operate the latch` and thereby raise the clamps, said latch holding; the clamps raised While the machine is at rest, a latch-releasing member independent lrom the cam, and means actuated there-` to spread the clamps after they have closed.

said cam device to the constantly-rotating member, a clamp-raising latch, means actuated by said cam device to operate the latch and thereby raise the clamps, said latch holding vthe clamps raised While the machine is at rest, a latch-releasing member independent 'from saidcam and operative duri 0 its initia'i movement to release the latch tlieeby to ailoW the clamps to close and during its further movement to spread the clamps.

19. In a sewing machine, the combination 'With stitch-'forming mechanism, of driving and stopping mechanism therefor, two Work clamps for holding the .vorlr, a spring device for holding the clamps yieldingly against the Work, a rotary Vcam device, a constantlyrotating member, means actuated by the driving and stopping mechanism in bringing the stitch-forming mechanism to rest to couple said. cam device to the constantly-rotating member, a clamp-raising latch, means ac- Y tuated by` said campdevice to operate the latch and thereby vraise the clamps, said latch holding the clamps raised While the machine is at at rest, a cam device for spreading the clamps anda rmovable actuating member operative duringitsl initial movement to release the latch and during further movement to actuate the cam device to spread the clamps.

20. In a sewing machine, the combinationV ,With stitch-forming mechanism, of driving and stopping mechanism therefor, tWo Work clamps for holding the Work, a spring device Y for holding the. 'clampsy yieldingly againstV the Work, a rotary cam device, a constantlyrotating member, means actuated by the driving and stopping mechanism in bringing the .stitch-forming mechanism to rest to couple saidicam` -device to the constantly-rotating member, a .clamp-raising latch, means actuated by said cam device to operate the latch Y and therebyraise the clamps, said latch holdingclamps raised While the machine is at rest, an actuating device and connections lwhereby during the initial movement of the actuating device the latch will be released to ,allow the clamps to close and during further movement the clamps will be spread and Aduring lstill further movement the driving 1 'mechanism'will be rendered operative to start the stitch-forming mechanism inl operation. 21.[Ina sewing machine, the combination with'stitch-forming mechanism, of driving and stopping mechanism therefor, Workclamping means for holding the Work, a spring to hold the clamping means yieldingly against the Work, a latch for holding the clamping means raised against the action of the spring, a starting device by Which the driving and stopping mechanism is set in operation to start the machine, latch-releasing means, connections between said starting device and both the latch-releasing means and the driving and stopping mechanism, the latter connections having a lost motion, whereby when the starting device is operated its initial movement Will actuate the latchreleasing means thereby releasing` the latch and allowing the clamping means to close against the Work and subsequent movement Will et the driving mechanism in operation.

In testimony whereof, l have signed my name to this specification.

AXEL F. CARLSON. 

